Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




SOLAR SCIENCE
Coronal Heating Theory Tested In NASA Sounding Rocket Mission
by Karen C. Fox
Greenbelt MD (SPX) Aug 05, 2014


The sounding rocket carrying the EUNIS experiment launches from the White Sands Missile Range in New Mexico on April 23, 2013. Image courtesy NASA. Watch a video on the research here.

Scientists have recently gathered some of the strongest evidence to date to explain what makes the sun's outer atmosphere so much hotter than its surface. The new observations of the small-scale extremely hot temperatures are consistent with only one current theory: something called nanoflares - a constant peppering of impulsive bursts of heating, none of which can be individually detected -- provide the mysterious extra heat.

What's even more surprising is these new observations come from just six minutes worth of data from one of NASA's least expensive type of missions, a sounding rocket.

The EUNIS mission, short for Extreme Ultraviolet Normal Incidence Spectrograph, launched on April 23, 2013, gathering a new snapshot of data every 1.3 seconds to track the properties of material over a wide range of temperatures in the complex solar atmosphere.

The sun's visible surface, called the photosphere, is some 6,000 Kelvins, while the corona regularly reaches temperatures which are 300 times as hot.

"That's a bit of a puzzle," said Jeff Brosius, a space scientist at Catholic University in Washington, D.C., and NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Things usually get cooler farther away from a hot source. When you're roasting a marshmallow you move it closer to the fire to cook it, not farther away."

Brosius is the first author of a paper on these results appearing in the Aug. 1, 2014, edition of The Astrophysical Journal.

Several theories have been offered for how the magnetic energy coursing through the corona is converted into the heat that raises the temperature. Different theories make different predictions about what kind of - and what temperature - material might be observable, but few observations have high enough resolution over a large enough area to distinguish between these predictions.

The EUNIS rocket, however, was equipped with a very sensitive version of an instrument called a spectrograph. Spectrographs gather information about how much material is present at a given temperature, by recording different wavelengths of light.

To observe the extreme ultraviolet wavelengths necessary to distinguish between various coronal heating theories, such an instrument can only work properly in space, above the atmosphere surrounding Earth that blocks that ultraviolet light.

So EUNIS flew up nearly 200 miles above the ground aboard a sounding rocket, a type of NASA mission that flies for only 15 minutes or so, and gathered about six minutes worth of observations from above the planet's air.

During its flight, EUNIS scanned a pre-determined region on the sun known to be magnetically complex, a so-called active region, which can often be the source of larger flares and coronal mass ejections. As light from the region streamed into its spectrograph, the instrument separated the light into its various wavelengths.

Instead of producing a typical image of the sun, the wavelengths with larger amounts of light are each represented by a vertical line called an emission line. Each emission line, in turn, represents material at a unique temperature on the sun. Further analysis can identify the density and movement of the material as well.

The EUNIS spectrograph was tuned into a range of wavelengths useful for spotting material at temperatures of 10 million Kelvin - temperatures that are a signature of nanoflares.

Scientists have hypothesized that a myriad of nanoflares could heat up solar material in the atmosphere to temperatures of up to 10 million Kelvins. This material would cool very rapidly, producing ample solar material at the 1 to 3 million degrees regularly seen in the corona.

However, the faint presence of that extremely hot material should remain. Looking over their six minutes of data, the EUNIS team spotted a wavelength of light corresponding to that 10 million degree material.

To spot this faint emission line was a triumph of the EUNIS instrument's resolution. The spectrograph was able to clearly and unambiguously distinguish the observations representing the extremely hot material.

"The fact that we were able to resolve this emission line so clearly from its neighbors is what makes spectroscopists like me stay awake at night with excitement," said Brosius. "This weak line observed over such a large fraction of an active region really gives us the strongest evidence yet for the presence of nanoflares."

There are a variety of theories for what mechanisms power these impulsive bursts of heat, the nanoflares. Moreover, other explanations have been offered for what is heating the corona.

Scientists will continue to explore these ideas further, gathering additional observations as their tools and instruments improve. However, no other theory predicts material of this temperature in the corona, so this is a strong piece of evidence in favor of the nanoflare theory.

"This is a real smoking gun for nanoflares," said Adrian Daw, the current principal investigator for EUNIS at Goddard.

"And it shows that these smaller, less expensive sounding rockets can produce truly robust science."

In addition to having a lower cost, sounding rockets offer a valuable test bed for new technology that may subsequently be flown on longer-term space missions. Another advantage of sounding rockets is that the instruments parachute back to the ground so they can be recovered and re-used.

The EUNIS mission will be re-tuned to focus on a different set of solar wavelengths - ones that can also spot the extremely high temperature material representative of nanoflares -- and fly again sometime in 2016.

EUNIS was supported through NASA's Sounding Rocket Program at the Goddard Space Flight Center's Wallops Flight Facility in Virginia. NASA's Heliophysics Division manages the sounding rocket program. EUNIS launched from the White Sands Missile Range in New Mexico. At the time of flight, the principal investigator for EUNIS was Doug Rabin at Goddard.

.


Related Links
Goddard Space Flight Center
Solar Science News at SpaceDaily






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SOLAR SCIENCE
Scientist underlines threat of inevitable "solar super-storms"
London, UK (SPX) Aug 05, 2014
In this month's issue of Physics World, Ashley Dale from the University of Bristol warns of the "catastrophic" and "long-lasting" impacts of "solar super-storms" and the dangers we face if the threat continues to go unnoticed. Dale, who was a member of an international task force - dubbed SolarMAX - set up to identify the risks of a solar storm and how its impact could be minimized, explai ... read more


SOLAR SCIENCE
August supermoon will be brightest this year

Manned Moon Mission to Cost Russia $2.8 Bln

Tidal forces gave moon its shape

Riddle of bulging Moon solved at last

SOLAR SCIENCE
NASA Mars Curiosity Rover: Two Years and Counting on Red Planet

Robotic Rock Climbers Could Uncover Clues to Mars' Past

Russia To Construct Landing Pad For ExoMars Mission

NASA Mars Rover Curiosity Nears Mountain-Base Outcrop

SOLAR SCIENCE
NASA's Space Launch System Boosters Office Completes Critical Design Review

NASA, Navy Prepare for Orion Spacecraft to Make a Splash

Orion spacecraft recovery practiced at sea

NASA Upgrades Its 3-D Spacecraft App

SOLAR SCIENCE
China's Circumlunar Spacecraft Unmasked

China to launch HD observation satellite this year

Lunar rock collisions behind Yutu damage

China's Fast Track To Circumlunar Mission

SOLAR SCIENCE
Robonaut Upgrades, Spacewalk Preps and Cargo Ops for ISS Crew

US EVAa Delayed; Crew Preps For Russian EVA, Robonaut Upgrades

Europe's Fifth and Final Resupply Ship Launches to Station

Science and Spacesuit Work While ATV-5 Preps for Launch

SOLAR SCIENCE
US Launches Two Surveillance Satellites From Cape Canaveral

United Launch Alliance Marks 85th Successful Launch

US aerospace firm outlines New Zealand-based space program

China to launch satellite for Venezuela

SOLAR SCIENCE
Planet-like object may have spent its youth as hot as a star

Young binary star system may form planets with weird and wild orbits

Hubble Finds Three Surprisingly Dry Exoplanets

Astronomers come up dry in search for water on exoplanets

SOLAR SCIENCE
Disney develops tool to design inflatable characters and structures

NASA Experts, Russia Sign Radiation Safety Protocol Despite Sanctions

New material structures bend like microscopic hair

Military training and simulation revenues to remain steady




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.